Counties Passed through: Cherokee
Generally, the mother road has remained as it is now, cutting a corner in the southeast corner of Kansas in Cherokee County. When US 66 was first designated in 1926, the segment form Baxter Springs north and east to Missouri was hard surfaced, with the remainder of the route to the south remaining a dirt road. The dirt segment was graveled by 1928 and paved by 1929.
In 1960, The Riverton-Baxter Springs segment was realigned to the east. At some point (possibly around the same time), US 66 was moved from Front Street to 7th Street in Galena, with a new roadway running diagonally to 7th Street in Joplin, Missouri.
The elimination of what was left of US 66 from Joplin west to Sanders, Arizona was approved by the American Association of State Highway and Transportation Officials on June 26, 1985. At the same time, a new route, US 69 Alternate was designated, replacing US 66 south and west of Riverton. The remainder of the road east of Riverton was re-designated as K-66.